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5.3L / 6.2L V8 · AFM & DFM CYLINDER DEACTIVATION

GM AFM/DFM lifter failure

A ticking noise on a 5.3L or 6.2L V8 is a documented failure mode with real GM diagnostic bulletins behind it — but no settlement or warranty extension exists yet. Paste a VIN below to see if a Silverado, Sierra, Tahoe, Yukon, Suburban, or Escalade is this exact engine.

Manufacturer TSB (diagnostic)Litigation ongoing — no settlement

Real TSB, no repair-cost program — yet

GM has published diagnostic bulletins acknowledging the symptom (TSB 15-06-01-002F/H, 19-NA-218, PIP5259D, PIP6101A) — that's real, citable documentation that this is a known factory issue, not a guess. What doesn't exist yet is a settlement: a consolidated class action covering Silverado, Sierra, Tahoe, Yukon, Suburban, and Escalade is still active and unresolved in federal court. Don't walk into a dealer assuming there's a program to ask for by number the way there is for Ford's 21N03 or Subaru's CVT warranty extension — there isn't, at least not yet.

Where this shows up on a CurbSpec sheet

Both GM families in the reviewed library cite this as a known issue, tiered as a manufacturer bulletin:

Ram's 5.7L HEMI has a related but distinct issue — MDS lifter and camshaft wear — with no official TSB at all, only owner reports and litigation. See the Ram 1500 sheet for that one; it's a different defect from the exhaust-manifold tick Stellantis does have a TSB for.

Frequently asked

What is AFM/DFM lifter failure?
Active Fuel Management (AFM, on Gen IV 5.3L/6.2L engines) and Dynamic Fuel Management (DFM, on Gen V 5.3L L84/6.2L L87 engines) both deactivate cylinders to save fuel. A lifter's internal locking pin can stick or collapse — often from oil aeration — causing a ticking noise, misfire codes (P0300-series), rough running, or stalling.
Is there a GM TSB for this?
Yes — GM has published real diagnostic bulletins: TSB 15-06-01-002F/H (engine misfire/tick, DTC P0300), TSB 19-NA-218, and dealer diagnostic procedures PIP5259D and PIP6101A. These document how to diagnose the failure; they aren't a repair-cost program.
Is there a settlement or extended warranty?
Not yet. A consolidated class-action lawsuit covering AFM/DFM lifter failure across Silverado, Sierra, Tahoe, Yukon, Suburban, and Escalade is active in the Eastern District of Michigan, but as of this writing it hasn't reached a settlement — so there's no established warranty extension to point to the way there is for Ford's cam phasers or Subaru's CVT. Don't assume goodwill coverage; ask your dealer directly.
Which vehicles and engines does this affect?
Any GM truck or SUV built on the 5.3L or 6.2L small-block V8 with cylinder deactivation — Silverado 1500, Sierra 1500, Tahoe, Yukon, Suburban, and Escalade, spanning both the older AFM generation and the newer DFM generation. CurbSpec's reviewed library currently covers Silverado/Sierra 1500 (gasoline) and the current Yukon/Tahoe/Suburban/Escalade generation specifically.
What does the repair cost?
Lifter and camshaft replacement typically runs $1,500–$5,000 depending on how much valvetrain damage occurred before the noise was diagnosed. If metal debris circulated through the oil system before it was caught, a full engine replacement may be needed.